As a low thermal expansion Fe-based alloy, Fe—Ni-based and Fe—Ni—Co-based alloys such as Fe-36% Ni-based, Fe-42% Ni-based, Fe-29% Ni-17% Co-based alloys are well known. These alloys exhibit an extremely low thermal expansion coefficient near room temperature due to Invar effect. In addition, low thermal expansion alloys having high strength are disclosed in JP-B-S41-2767 (PTL 1), JP-A-S59-56563 (PTL 2), and JP-A-H04-218642 (PTL 3). In these alloys, it is possible to obtain high strength and a relatively low thermal expansion coefficient not only at room temperature but also at a certain degree of high temperature. In addition, low thermal expansion alloys having high strength of which oxidation resistance is improved at high temperature are disclosed in JP-A-S53-6225 (PTL 4), JP-A-2001-234292 (PTL 5).